Modifying LnHPDO3A Chelates for Improved T 1 and CEST MRI Applications

Giuseppe Ferrauto, Daniela Delli Castelli, Loredana Leone, Mauro Botta, Silvio Aime, Zsolt Baranyai, Lorenzo Tei

Research output: Contribution to journalArticle

4 Citations (Scopus)


The new ligand HPDO3MA [(R,R,R,R)-10-(2-hydroxypropyl)-α,α′,α′′-trimethyl-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid] was designed to combine and optimize the chemical properties of the macrocyclic ligands HPDO3A and DOTMA. The presence of the methyl groups on the acetic pendant arms of HPDO3A is expected to rigidify the structure of the ligand and favor an increase of the kinetic inertness of the Ln complexes. 1 H NMR spectra of Eu(HPDO3MA) displayed the presence of two pairs of diastereoisomers: SAP (square antiprismatic) and TSAP (twisted square antiprismatic) isomers (56 and 44 %, respectively). In addition, 1 H and 17 O relaxometric NMR studies of Gd(HPDO3MA) showed approximately a 10 % increase in relaxivity and a faster water exchange rate with respect to Gd(HPDO3A). Moreover, a detailed chemical exchange saturation transfer (CEST) characterization of Yb(HPDO3MA) displayed a sensitivity about two times larger than that of Yb(HPDO3A) both in phantom and in cell labeling experiments. Finally, the kinetic inertness of Yb(HPDO3MA) was measured to be twice as high as that of Yb(HPDO3A), with a dissociation half-life at physiological pH of about 2500 years.

Original languageEnglish
Pages (from-to)4184-4193
Number of pages10
JournalChemistry - A European Journal
Issue number16
Publication statusPublished - Mar 15 2019


  • cell labeling
  • kinetic inertness
  • lanthanides
  • macrocycles
  • relaxometry

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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  • Cite this

    Ferrauto, G., Delli Castelli, D., Leone, L., Botta, M., Aime, S., Baranyai, Z., & Tei, L. (2019). Modifying LnHPDO3A Chelates for Improved T 1 and CEST MRI Applications Chemistry - A European Journal, 25(16), 4184-4193.